Your Ad HereJefferson Davis County is a county located in the U.S. state of Mississippi. As of 2016, the population was 11,385. Its county seat is Prentiss.HistoryIt is named in honor of Mississippi Senator and Confederate President Jefferson Davis. The county was carved out of Covington and Lawrence counties in March 1906. Governor James K. Vardaman signed the bill creating the county on May 9, 1906.